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linux/Documentation/ABI/testing/sysfs-class-backlight
Mauro Carvalho Chehab 13d6f96750 docs: ABI: sysfs-class-backlight: unify ambient light zone nodes
./scripts/get_abi.pl is warning about duplicated symbol
definition:

	Warning: /sys/class/backlight/<backlight>/l1_daylight_max is defined 2 times:  ./Documentation/ABI/testing/sysfs-class-backlight-driver-adp8870:4  ./Documentation/ABI/testing/sysfs-class-backlight-adp8860:12

What happens is that 3 drivers use the same pattern to report
max and dim setting for different ambient light zones.

It should be noticed that the adp8870 doc was missing an
entry for l1_daylight_dim, which was fixed on this patch.

While the ambient light zone is device-specific, the sysfs
definition is actually common. So, unify them at:

	Documentation/ABI/testing/sysfs-class-backlight

and use as the contact point, the e-mail reported by
get_maintainers.pl for the subsystem.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c13c6ebd03cd04a0d15d89018f8d529918fc0a73.1621413933.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-05-20 13:44:14 -06:00

187 lines
6.3 KiB
Plaintext

What: /sys/class/backlight/<backlight>/scale
Date: July 2019
KernelVersion: 5.4
Contact: Daniel Thompson <daniel.thompson@linaro.org>
Description:
Description of the scale of the brightness curve.
The human eye senses brightness approximately logarithmically,
hence linear changes in brightness are perceived as being
non-linear. To achieve a linear perception of brightness changes
controls like sliders need to apply a logarithmic mapping for
backlights with a linear brightness curve.
Possible values of the attribute are:
unknown
The scale of the brightness curve is unknown.
linear
The brightness changes linearly with each step. Brightness
controls should apply a logarithmic mapping for a linear
perception.
non-linear
The brightness changes non-linearly with each step. Brightness
controls should use a linear mapping for a linear perception.
What: /sys/class/backlight/<backlight>/ambient_light_level
Date: Apr, 2010
KernelVersion: v2.6.35
Contact: Michael Hennerich <michael.hennerich@analog.com>
Description:
(RO) Get conversion value of the light sensor.
The value is automatically updated every 80 ms when the
light sensor is enabled.
The value range is device-driver specific:
For ADP8870:
It returns integer between 0 (dark) and 8000 (max ambient
brightness).
For ADP8860:
It returns a 13-bits integer.
What: /sys/class/backlight/<backlight>/ambient_light_zone
Date: Apr, 2010
KernelVersion: v2.6.35
Contact: Michael Hennerich <michael.hennerich@analog.com>,
device-drivers-devel@blackfin.uclinux.org
Description:
(RW) Read or write the specific brightness level at which the
backlight operates.
The value meaning is device-driver specific:
For ADP8860:
== ==========================
0 Off: Backlight set to 0 mA
1 Level 1: daylight
2 Level 2: bright
3 Level 3: dark
== ==========================
For ADP8870:
== ==========================
0 Off: Backlight set to 0 mA
1 Level 1: daylight
2 Level 2: bright
3 Level 3: office
4 Level 4: indoor
5 Level 5: dark
== ==========================
Writing 0 returns to normal/automatic ambient light level
operation.
It can be enabled by writing the value stored in
/sys/class/backlight/<backlight>/max_brightness to
/sys/class/backlight/<backlight>/brightness.
What: /sys/class/backlight/<backlight>/<ambient light zone>_max
Date: Sep, 2009
KernelVersion: v2.6.32
Contact: device-drivers-devel@blackfin.uclinux.org
Description:
Control the maximum brightness for <ambient light zone>
on this <backlight>. Values are between 0 and 127. This file
will also show the brightness level stored for this
<ambient light zone>.
The <ambient light zone> is device-driver specific:
For ADP5520 and ADP5501, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
daylight /sys/class/backlight/<backlight>/daylight_max
office /sys/class/backlight/<backlight>/office_max
dark /sys/class/backlight/<backlight>/dark_max
=========== ================================================
For ADP8860, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max
l2_office /sys/class/backlight/<backlight>/l2_office_max
l3_dark /sys/class/backlight/<backlight>/l3_dark_max
=========== ================================================
For ADP8870, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max
l2_bright /sys/class/backlight/<backlight>/l2_bright_max
l3_office /sys/class/backlight/<backlight>/l3_office_max
l4_indoor /sys/class/backlight/<backlight>/l4_indoor_max
l5_dark /sys/class/backlight/<backlight>/l5_dark_max
=========== ================================================
See also: /sys/class/backlight/<backlight>/ambient_light_zone.
What: /sys/class/backlight/<backlight>/<ambient light zone>_dim
Date: Sep, 2009
KernelVersion: v2.6.32
Contact: device-drivers-devel@blackfin.uclinux.org
Description:
Control the dim brightness for <ambient light zone>
on this <backlight>. Values are between 0 and 127, typically
set to 0. Full off when the backlight is disabled.
This file will also show the dim brightness level stored for
this <ambient light zone>.
The <ambient light zone> is device-driver specific:
For ADP5520 and ADP5501, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
daylight /sys/class/backlight/<backlight>/daylight_dim
office /sys/class/backlight/<backlight>/office_dim
dark /sys/class/backlight/<backlight>/dark_dim
=========== ================================================
For ADP8860, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim
l2_office /sys/class/backlight/<backlight>/l2_office_dim
l3_dark /sys/class/backlight/<backlight>/l3_dark_dim
=========== ================================================
For ADP8870, <ambient light zone> can be:
=========== ================================================
Ambient sysfs entry
light zone
=========== ================================================
l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim
l2_bright /sys/class/backlight/<backlight>/l2_bright_dim
l3_office /sys/class/backlight/<backlight>/l3_office_dim
l4_indoor /sys/class/backlight/<backlight>/l4_indoor_dim
l5_dark /sys/class/backlight/<backlight>/l5_dark_dim
=========== ================================================
See also: /sys/class/backlight/<backlight>/ambient_light_zone.